The 2021 Chevrolet Tahoe full-size SUV can get up to 28 mpg highway when equipped with a 3.0-liter turbodiesel inline-6, Chevy announced on Thursday. The turbodiesel gets an EPA-rated 21 mpg city, 28 highway, 24 combined in rear-wheel-drive models. Four-wheel drive drops it to 20/26/22 mpg. Chevy claims it's best in class fuel economy for...